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* osf.S using 3 operand jmp and jsr
@ 2015-02-25 13:19 John E. Malmberg
  2015-02-25 16:41 ` Richard Henderson
  0 siblings, 1 reply; 2+ messages in thread
From: John E. Malmberg @ 2015-02-25 13:19 UTC (permalink / raw)
  To: libffi-discuss

I noticed that the src/alpha/osf.S is using 3 operand jmp and jsr 
instructions.

What does gas do with the third operand?

The VMS Macro 64 assembler only supports 2 operand jmp/jsr instructions.

Regards,
-John

^ permalink raw reply	[flat|nested] 2+ messages in thread

* Re: osf.S using 3 operand jmp and jsr
  2015-02-25 13:19 osf.S using 3 operand jmp and jsr John E. Malmberg
@ 2015-02-25 16:41 ` Richard Henderson
  0 siblings, 0 replies; 2+ messages in thread
From: Richard Henderson @ 2015-02-25 16:41 UTC (permalink / raw)
  To: John E. Malmberg, libffi-discuss

On 02/25/2015 03:18 AM, John E. Malmberg wrote:
> I noticed that the src/alpha/osf.S is using 3 operand jmp and jsr instructions.
> 
> What does gas do with the third operand?

It encodes it in bits 0:13 as a branch prediction hint.

> The VMS Macro 64 assembler only supports 2 operand jmp/jsr instructions.

Since it's a hint, you can just drop it.


r~

^ permalink raw reply	[flat|nested] 2+ messages in thread

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